Chapter 1. Introduction
GFK-2571N
May 2018
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1.6.8
Systems that use PROFINET System Redundancy (PNSR)
PACSystems support S2 type PNSR, as diagrammed in Figure 13.
The ‘S’ d
enotes that the IO Device has single
network support.
PROFINET defines an ‘R’ option in which the IO Device may have redundant network
interfaces which could be on different networks. The
‘2’ d
enotes that the network supports two connections as
a set.
Note that in each case the firmware installed in the PROFINET Controller and in the PROFINET Device must
themselves support PNSR. PNSR allows a set of Hot standby CPU controllers to have an active and hot backup
connection to an IO device, so that if something fails in one CPU controller, the other CPU controller can
continue IO operations without disruption.
PNSR relies entirely on PROFINET features to support this configuration. PACSystems only supports PNSR in
Dual HWC Hot Standby systems. Within a PNSR system, simplex IO devices may be controlled by one CPU
Controller in addition to redundant IO devices which are controlled by the Active CPU of the Hot Standby
system. When the CPU controller which is controlling a simplex IO Device is stopped, that IO Device is lost.
The PROFINET PNSR Network may be either Ring or Star formation. Using a Ring formation with the Media
Redundancy Protocol (refer to Chapter 6), is often useful with PNSR systems since a single cable failure is
handled by MRP allowing both IO Controllers to maintain connection with the IO devices.
Figure 13: PROFINET System Redundancy S2
